GUANTANAMO BAY U.S. NAVAL BASE, Cuba, Jan 28 (Reuters) - -L awyers for five alleged conspirators who attacked America onSept. 11 and say they were tortured in secret CIA prisons haveasked a U.S. military judge to order that the prisons bepreserved as evidence.

The issue is one of more than two dozen on the docket for aweek of pretrial hearings that began on Monday in the war crimestribunal at the Guantanamo Bay U.S. Naval Base in Cuba.

The defendants include Khalid Sheikh Mohammed, the accusedmastermind of the hijacked plane attacks that killed 2,976people on Sept. 11, 2001. He wore a camouflage jacket to courtover his white tunic and defiantly refused to answer the judge'squestions.

Defense lawyers also have asked the judge to order the U.S.government to turn over all White House or Justice Departmentdocuments authorizing the CIA to move suspected al Qaedacaptives across borders without judicial review and hold andinterrogate them in secret prisons after the Sept. 11 attacks.

President George W. Bush announced in 2006 that the Sept. 11defendants were among a group of "high-value" captives sent toGuantanamo from the secret prisons.

The CIA has acknowledged that Mohammed was subjected to thesimulated drowning technique known as waterboarding. Thedefendants said they were also subjected to sleep deprivation,threats, and being chained in painful positions.

The defense lawyers will argue that their clients' treatmentwas illegal pretrial punishment and constituted "outrageousgovernment misconduct" that could justify dismissal of thecharges, or at least spare the defendants from execution ifconvicted.

"By its nature, torture affects the admissibility ofevidence, the credibility of witnesses, the appropriateness ofpunishment and the legitimacy of the prosecution itself," thedefense lawyers wrote in court documents.

At least one potential witness was also held in the CIAprisons and his treatment could raise questions about theadmissibility of his testimony, said James Connell, defenseattorney for Mohammed's nephew, defendant Ali Abdul-Aziz Ali.

The chief prosecutor, Brigadier General Mark Martins, saidthe prosecution does not plan to introduce any evidence obtainedfrom the defendants or anyone else via torture, cruelty orinhuman treatment - which is prohibited by U.S. law andinternational treaty.

In a departure from the Bush administration, the Obamaadministration has made it clear that any interrogationtechniques must adhere to those long established in the armyfield manual, which prohibits torture.

The defendants have been in U.S. custody for a decade, butthere are still numerous legal and evidentiary issues that mustbe resolved before their trial begins on charges that includemurder, hijacking, terrorism and attacking civilians.

ABU GHRAIB PRISON

The judge presiding over the Sept. 11 trial, Army ColonelJames Pohl, ordered in 2004 that the Abu Ghraib prison in Iraqbe preserved as a "crime scene." He was at the time presidingover the trial of U.S. military police officers accused oftorturing and photographing prisoners at Abu Ghraib.

Iraq was then under U.S. occupation. It was unclear whetherPohl had authority to order the preservation of the CIA prisons, whose location the government has kept secret, arguingthat disclosure could threaten U.S. national security and putallies at risk.

Polish prosecutors are investigating allegations that one ofthe sites was in Poland, and there is evidence the CIA set upothers in Romania, Lithuania and Thailand, according to reportsby the Council of Europe and the United Nations.

Lawyers for the Sept. 11 defendants first made the requestfor preservation of the secret CIA prisons under seal inSeptember of last year. The request was unsealed about a monthlater. But this week's pre-trial hearing marks the first time ithas been presented in the Guantanamo court.

Before considering the CIA prisons issue, the court onMonday began slogging through issues such as whether thedefendants had agreed to add lawyers to two defense teams anddrop one from another and whether they must show up in court forpretrial hearings.

When two of them refused to answer whether they had approvedthe personnel changes, the judge took their lawyers' word for itthat they had.

But he said he would not grant their request to skip somecourt sessions unless they first acknowledged vocally that theyunderstood they had the right to be present for discussions thatcould affect their legal rights.

"They're going to have to tell me out of their own mouths,or they'll be here," Pohl said.

After a chaotic May 2012 arraignment session that dragged onfor 13 hours, the defendants have alternated between refusingto speak to the judge and making accusatory statements againstthe United States. Although they largely ignored the judge onMonday, they whispered to their lawyers and appeared to bereading legal documents.

Mohammed and his nephew are Pakistani citizens. The otherdefendants are Walid bin Attash and Ramzi Binalshibh, bothYemenis, and Mustafa al Hawsawi, a Saudi.